1. Field
Embodiments of the present invention generally relate to techniques for processing requests from clients requesting data from a web server and, more specifically, to handling individual client requests based on constraints suggested by the clients.
2. Description of Related Art
Digital content distribution systems typically include a content server, a content player, and a communications network connecting the content server to the content player. The content server is configured to store files (or “streams”) available for download from the content server to the content player. Each stream may provide a digital version of, e.g., a movie, a television program, a sporting event, a staged or live event captured by recorded video, etc. Streams may also provide media content created specifically for distribution online. Content files stored on the content server typically are typically organized according to playback chronology and may store audio data and/or video data.
Playback frequently involves a technique known as “streaming,” where a content server transmits portions of a stream to a content player, which in turn decodes and initiates playback on the a client device while subsequent portions of the stream are received. To account for variable latency and bandwidth within the communications network, a content buffer on the client device may be used to queue incoming portions of the stream ahead of the portions actually being played. During moments of network congestion (which leads to lower available bandwidth) less data is added to the buffer, which may drain down as data is being de-queued to support playback at a certain playback bit rate. However, during moments of high network bandwidth, the buffer is replenished and additional buffer time is added until the buffer is generally full again. In practical systems, the buffer may queue data corresponding to a time span ranging from seconds to more than a minute.
Streaming digitally encoded audiovisual (AV) programs (including feature length films and television programs) over the Internet has become popular as the availability of high-bandwidth Internet communication has increased, and a variety of different streaming media protocols are available for transmitting media streams to the client. Although many of these protocols were conceived of to transmit media streams from a server to a conventional computing system (e.g., a typical desktop PC or laptop computer), the streaming approach is also being used to transmit streaming media to a variety of end-user client devices; including, e.g., mobile telephones, tablet and net-book computing devices, console and handheld video game systems, digital video recorders (DVRs), DVD players, and dedicated media streaming devices, (e.g., the Roku® set-top box), etc.